Poly(p-phenylene terephthalamide)-Derived Nitrogen-Doped Hard Carbon Microspheres for High-Performance Lithium-Ion Capacitors

초록

Lithium-ion capacitors (LICs) combine battery-type and capacitor-type charge-storage mechanisms, but their performance critically depends on the compatibility between anode and cathode materials. In this study, a precursor-unified LIC architecture was developed using poly(p-phenylene terephthalamide) (PPTA)-derived carbon materials as both electrodes. Nitrogen-doped hard carbon microparticles (NHCM), obtained via direct carbonization of PPTA microparticles, were employed as the battery-type anode, while KOH-activated PPTA-derived porous hard carbon (ANHCM) served as the capacitor-type cathode. The NHCM anode delivered initial discharge and charge capacities of 701 and 505 mA h g(-1), respectively, at a current density of 0.05 A g(-1), corresponding to an initial coulombic efficiency of similar to 72%, whereas the ANHCM-1.0 cathode exhibited a specific capacity of similar to 109 mA h g(-1) at 0.1 A g(-1) with nearly 100% coulombic efficiency over 5,000 cycles. After electrochemical prelithiation and optimization of the electrode mass ratio (1:3), the assembled NHCM//ANHCM-1.0 LIC operated stably within a voltage window of 0.1-4.0 V, delivering an energy density of 155 Wh kg(-1) at 226 W kg(-1) and retaining 66 Wh kg(-1) at a high power density of 9,535 W kg(-1), with a capacity retention of 63.8% after 5,000 cycles. These results demonstrate that PPTA-derived carbon materials provide a precursor-unified and scalable strategy for constructing competitive LIC systems.

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